SICK FX0-GMOD User Manual

Measures against common causes of error
In par
ticular when both encoders are used for redundant monitoring of an axis, the
following possibilities must be taken into account, among others:
•
The common GND connection can be interrupted by the common connecting cable
on the FX3-MOCx for both encoders as a common reference potential for both
encoders.
•
The supply voltage for the encoder can be too low or completely interrupted.
•
The commonsupply voltage for both encoders can be too high. This may damage
both encoders. When using PELV/SELV voltage supplies without additional protec‐
tive measures, you must usually assume a voltage increase to 60V here.
•
The entire encoder connection to the FX3-MOCx can be interrupted.
The following options are available to detect errors in the encoder system with the
Flexi Soft safety controller:
•
Use at least one encoder/motor feedback connection box. A description of this
function can be found in the “FlexiSoft in the FlexiSoft Designer Configuration
Software” and “FlexiSoft in the Safety Designer Configuration Software” operating
instructions in the “Encoder connection type and monitoring of ID identifier” sec‐
tion.
•
Use a sine/cosine encoder with activated sine/cosine analog voltage monitoring.
7)
A description of this function can be found in the “FlexiSoft in the FlexiSoft
Designer Configuration Software” and “FlexiSoft in the Safety Designer Configu‐
ration Software” operating instructions in the “Sine-cosine analog voltage monitor‐
ing” section.
•
Use an SSI encoder with evaluation of error bits. A bit in the SSI data is needed
which takes on an inverted state if the observed error occurs, for example
because the supply voltage of the encoders is too low or because one or several
of the cables from the encoder to the FX3-MOCx are disconnected. A description
of this function can be found in the “FlexiSoft in the FlexiSoft Designer Configu‐
ration Software” and “FlexiSoft in the Safety Designer Configuration Software”
operating instructions in the “SSI encoder” section.
•
There is no possibility to detect faults immediately using the encoder signals when
using A/B incremental encoders.
8)
•
Additionally, in certain cases there will be the option to check the plausibility of the
encoder’s motion signal using another signal from the process in conjunction with
the logic of the motion control module and main module, e.g. with a signal "drive
running/not running".
•
Use separate voltage supplies for both encoders.
There are the following options to control the voltage increase within the limits of a
PELV/SELV voltage supply, as long as the faults to be accepted are not controlled by
one of the selected monitoring functions:
►
Use separate voltage supplies for both encoders.
►
Use encoders that are equipped for the increased supply voltage to be accepted.
►
Either use the voltage supply of theFX3-MOCx module for the encoder (ENC1_24V
and/or ENC2_24V) directly or via the encoder/motor feedback connection unit. If
the supply voltage for the Flexi Soft system exceeds 35V at the system plug of the
main module, then the system switches into a safe state, i.e. the safety outputs
are switched off. In this way, safe switching off in the application in the event of a
voltage increase can be controlled. In this case, it is still possible for the encoder
to be damaged.
7)
C
onfigurable for sine/cosine encoders in the hardware configuration of the configuration software.
8)
This also applies for A/B incremental encoders with 2output pairs. Fault detection based on the inverted output signals would allow for
cable monitoring, although it would not be possible to detect all faults to be accepted in an A/B incremental encoder such as a static
state of the output level.
10 T
ROUBLESHOOTING
126
O P E R A T I N G I N S T R U C T I O N S | Flexi Soft Modular Safety Controller 8012478/1IG6/2023-02-24 | SICK
Subject to change without notice

SICK FX0-GMOD Specifications

General

Brand	SICK
Model	FX0-GMOD
Category	Controller
Language	English